Electron discharge device



Sept. 5, 1933. w KRAHL 1,926,008

ELECTRON DI SCHARGE DEVICE Filed Feb. 12, 1931 [Va/fer Lox/1's Era/L! @313 bis W Patented Sept. 5, i933 szaoos ELECTRQN DISCHARGE DEVICE if/alter Louis Krahl, Montclair, N. 3L, assignor,

by mcsne assignments, to Arcturus Development (Jompany, Newark, N. 31, a corporation of Delaware Application February 12, 1931. Serial No. 515,252?

8 Claims. (Cl. 25ii21.5)

This invention relates to electron discharge deode so as to electrically separate the two parts vices, and more particularly to the assembly of and prevent short circuiting of the filament. the electrodes therein. Grid 10 is preferably of a cylindrical character I The objects of the invention are to provide an composed of a plurality of convolutions of a heliimproved assembly structure of electrodes which cally wound wire, the grid being coaxial with the will obtain rigidity of parts; proper cooperation cathode and carried by a longitudinal rod 12 between the parts; maintenance of desired tube Within the grid andto which each convolution characteristics; avoidance of current leakage so t f iS Secured as by weldin Outside Of the far as possible; ready assembly of the parts with id is a ra d & Cylindrical anode this p minimum operation; simplicity of construction also being coaxia W th the d nd Cat de. and conformity to required standards; and to Th nod i pr r bly m de of heet m t l obtain other advantages and results as may be With the marginal e d Of e metal b U 0- brought out in the following des ri tion, gether after forming the cylinder and extending Referring to the accompanying drawing i radially from the cylindrical portion as a longiwhich like numerals of referen e indicate similar tildihal flange 14 and With the eXtl'eme edge of 70 parts th h t th Several views; the flange encircling and secured to one of the Figure 1 is a side elevation of an electrode aseXtleme upstanding rods 6- sembly shown mounted in an envelope b k The construction of the anode constitutes one away to di clo e the assembly; d of the features of the present invention. It will Figure 2 i a sectional i on line 2W2 of be noted that tl e anode provides a pair of ex- Fig 1 tensions 15 at its upper end on opposite sides In the specific embodiment of the invention of the cylindrical p f t an d the upp illustrated in said drawing, reference numeral 1 dgesof these extensions forming upw indicates an envelope, usually constructed of ihg Sheiilders- The W d of the flange glass and providing in the finished item an up" extends below the lower edge of the cylindrical standing stem 2 within the envelope and having a portiel'l 0f the anode, as a and the lower press 3 by which a plurality ofvupstanding rods edge of this extension likewise provides a downare sealed-in, the lower ends of certain of the weirdly facing sheilideli Above and below h rods being connected to prongs l exterior of the anode, transverse to the s theleef, are a p r envelope and carried as su l by a b 5 t of parallel insulators l'l-17, and these insulators 0 ed at the lower end of the envelope. This strucengage W their fiat Su aces a ainst e Shou ture, as so far described, is common in the art fliers p d y the eXtehSiOhS Oh the a and may be varied in accord ith d i d or In order to hold the insulators assembled with common practice, respect to the anode, the upper extensions 15 As here shown, the sealed-in rods upstanding have small ta ears 18 extending through from the press are all in a com m bei the insulators and bent over at the upper side positioned in a row and the two extreme rods thereof, as Clearly Sh in The Jewel 6, 6 of the row are much longer than the other n i n 16 li ewi ha s 19 proj in rods, extending the full height i all of th 1 through the lower insulator and bent over beyond r 4 trodes. Between the extreme rods 6, 6 are three e Surface thereof. It will therefore be obother rods, two of which, as 7, 7, are preferably served that the insulators are spaced from the disposed symmetrically with espect to the 1011- de fo a jor pertieh 0f the end edges of gitudinal axis of the envelope and form supportt e a d T iS pa y true at the ing connections for the ends of a hair-pin filo, bottom of the anode where the entire circumment 8. The third intermediate rod, disposed tial ed e of the eylihehieal Portion of the between one of the filament rods and one of the anode is sp ced fr m th insul r nd h said extreme rods 6 constitutes a support 9 for nly contact of the anode wi h the in ulator t the lower end of a grid 10. the bottom of the anode is between the ex- The electrodes utilized in the present constructe s on 16 Of f a ge 14 Off-Set from the Cylindrition of electron discharge device comprise in adcal portion. This construction will accordingly dition to the upstanding hair-pin filament 8, a obtain a desired circulation and enable the gasetubular cathode 11 which surrounds the hair-pin ous contents of the envelope and residual gases filament and is heated thereby. Suitable insuwithin the cylindrical anode to be very thoroughlation, such as surface coating on one of the ly removed and to be affected by flashing the 110 parts is provided between the filament and cathtube. It will be understood that it is common practice in manufacture of electron discharge devices to provide a capsule 20 of magnesium or other material which is ultimately heated to higher temperature, or flashed for obtaining a combination with gases remaining in the tube to eliminate the same as gases. I have found that in order to fully accomplish this elimination of residual gases that the same must be eliminated from within the anode as well as elsewhere, and I have therefore provided the cathode which is open at its end nearest the capsule and open particularly at its lower end to encourage the downward movement of the gases as the same become affected by the flashing of the magnesium or other material. I find this elimination of residual gases is further aided by utilization of a foraminous anode, and as herein shown, the anode may have its middle portion perforated by a plurality of holes 21. The holes 21 are preferably confined to a middle band of the anode, and above and below the band of perforations the anode may have a circumferential rib 22 for reinforcing the same.

Insulators 17-17 are for purposes of mounting the several electrodes. As already described, the anode is secured to the insulators against extensions 15, 16 of the anode. Rod 6, supporting the anode, likewise extends through both of the insulators and similarly the opposite rod 6 extends through both the insulators, thereby keeping the insulators from twisting with respect to each other and conversely the insulators maintain the rods in proper spaced position. The grid supporting rod 12 projects beyond the ends oi. the grid through the two insulators, and conse quently the grid is held in proper relationship to the anode. The cathode likewise extends'through the insulators which have parts thereof engaging and centering the cathode. Accordingly, all of the electrodes are positioned with respect to each other by the insulators.

It is desirable to maintain the insulators in fixed parallel position. The upper insulator is secured by the plurality of cars 18, and in addition thereto a band connector 23 is attached to the end of the cathode projecting above the insulator, the band extending edgewise with respect to the insulator and passing around the projecting grid supporting rod out of contact therewith and toward the extreme rod 6. The insulator is radially slotted so that this band connector may have a downwardly projecting portion passing through the slot and then extending toward and around the rod 6. The portion of the band which is above the insulator obviously holds the insulator down and the underlying portion of the band holds the insulator up.

At the bottom of the electrodes the insulator 17 is secured near one end portion, as by engagement between the extension 16 and cars 19. At the other end portion a band support 24 edgewise with respect to the insulator surface is secured to the lower end portion of the grid supporting rod above the insulator, the band extending radially as far as its supporting rod, overlying the insulator and preventing the same from upward movement. In order to prevent the insulator from downward movement at this end, a wire bracket 25 is welded or otherwise secured to the extreme rod 6 immediately beneath the insulator, this bracket 25 constituting means for supporting capsule 20 heretofore referred to. It will accordingly be appreciatedthat both ends of this insulator are prevented from either upward or downward movement and are therefore held equally spaced from the ends of the upper insulator so that the two insulators are always parallel and rigid.

By the construction here shown, it will be observed that all of the rods sealed in the press constitute electric conductors, one of the extreme rods 6 being a conductor for the anode while the other extreme rod is a conductor for the cathode. The two symmetrically positioned middle'rods 77 are conductors for the filament or heater whereas the intermediate rod 9 is a conductor for the grid.

It is further to be understood that the present invention provides for assembly of the several electrodes independent of the sealed-in conductor rods. The several electrodes are first assembled with respect to the insulators and then slid lengthwise onto the extreme rods 66 until finally the grid band 24 engages conductor rod 9 and cathode band 23 slips onto its rod 6. In this position of parts the flange for the anode may then be welded to the rod 6, the ends of the filament may be welded to rods '7'Z, bands 23 and 24 may be welded to their respective rods 6 and 9, and the assembly of electrodes is then both mounted in position and electrically connected as required.

Obviously detail changes and modifications may be made in the construction and use of my improved electron discharge device without departing from the spirit or scope of the invention, and I do not wish to be understood as limiting myself to the exact construction shown or described except as set forth in the following claims when construed in the light of the prior art.

1. An electron discharge device having in combination with a cathode and grid, a support rod offset from said cathode and grid, an anode having a portion thereof surrounding the cathode and grid and having another portion thereof extending laterally therefrom forming a flange, the outer margin of said fiange portion encircling said support rod, one end of said flange having a length greater than the portion of the anode surrounding the grid and cathode, and a plate engaged by and positioned cross-wise of the flange at the end thereof having the greater length thereby spacing the plate from the portion of the anode surrounding the cathode and grid.

2. An electron discharge device having in combination with a cathode and grid, a support rod offset from said cathode and grid, an anode having a portion thereof surrounding the cathode and grid and having another portion thereof extending laterally therefrom forming a flange, the outer margin of said fiange portion encircling said support rod, the portion of the anode surrounding the grid and cathode having an extension at one end only projecting beyond the end of said flange and a plate engaged by and positioned cross-wise of the said extension on the anode thereby spacing the plate from the non extended portion of the anode.

.3. An electron discharge device having in combination with a cathode and grid, 2. support ro'd offset from said cathode and grid, a pair of insulatory plates transverse to the cathode receiving the end portions thereof, said support rod projecting through both of said plates, an anode disposed between said plates and having dissimilar extensions at opposite ends thereof for engaging said plates.

4. An electron discharge device having in combination with a cathode and grid, a support rod oifset from said cathode and grid, a pair of insulatory plates transverse to the cathode receiving the end portions thereof, said support rod projecting through both of said plates, an anode disposed between said plates having a portion thereof surrounding the cathode and grid and having another portion thereof extending laterally therefrom forming a flange, said flange having an extension engaging one of the plates for holding the grid and cathode surrounding portions spaced from said plate.

5. An electron discharge device having in combination with a cathode and grid, a support rod ofiset from said cathode and grid, a pair of insulatory plates transverse to the cathode receiving the end portions thereof, said support rod projecting through both of said plates, an anode disposed between said plates having a portion thereof surrounding the cathode and grid and having another portion thereof extending laterally therefrom forming a flange, said flange having an extension engaging one of the plates for holding the grid and cathode surrounding portions spaced from said plate, and the opposite end of said surrounding portion having means for spacing the flange from the other plate.

6. An electron discharge device having in combination with a cathode and grid, a pair of supporting rods on opposite sides of said cathode and grid, an anode carried by one of said rods, an insulating plate at one end of the anode secured thereto, and means for securing said plate with respect to the other support rod.

7. An electron discharge device having in combination with a cathode and grid, a pair of supporting rods on opposite sides of said cathode and grid, an anode carried by one of said rods, an insulating plate at one end of the anode secured thereto, a grid connection engaging said plate for holding it against movement in one direction, and means on the opposite side of said plate for holding it against movement in another direction.

8. An electron discharge device having in combination with a cathode and grid, a pair of supporting rods on opposite sides of said cathode and grid, an anode carried by one of said rods, an insulating plate at one end of the anode secured thereto, a grid connection engaging said plate or holding it against movement in one direction, and a bracket secured to the rod on the opposite side of the plate from the holding portion of said grid connection so as to cooperate with the grid connection for preventing the plate from movement in either direction.

WALTER LOUIS KRAHL. 

